Ion acceleration to 100 keV by the ExB wave mechanism in collision-less shocks

Stasiewicz, Krzysztof and Eliasson, Bengt (2021) Ion acceleration to 100 keV by the ExB wave mechanism in collision-less shocks. Monthly Notices of the Royal Astronomical Society, 508 (2). pp. 1888-1896. ISSN 0035-8711 (https://doi.org/10.1093/mnras/stab2739)

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Abstract

It is shown that ions can be accelerated to about 100 keV in the direction perpendicular to the magnetic field by the ExB mechanism of electrostatic waves. The acceleration occurs in discrete steps of duration being a small fraction of the gyroperiod and can explain observations of ion energization to 10 keV at quasi-perpendicular shocks and to hundreds keV at quasi-parallel shocks. A general expression is provided for the maximum energy of ions accelerated in shocks of arbitrary configuration. The waves involved in the acceleration are related to three cross-field current-driven instabilities: the lower hybrid drift (LHD) instability induced by the density gradients in shocks and shocklets, followed by the modified two-stream (MTS) and electron cyclotron drift (ECD) instabilities, induced by the ExB drift of electrons in the strong LHD wave electric field. The ExB wave mechanism accelerates heavy ions to energies proportional to the atomic mass number, which is consistent with satellite observations upstream of the bow shock and also with observations of post-shocks in supernovae remnants. The results are compared with other acceleration mechanisms traditionally discussed in the literature.

  • Item type:Article
    ID code:77842
    Dates:
    Date
    Event
    7 October 2021
    Published
    24 September 2021
    Published Online
    21 September 2021
    Accepted
    8 July 2021
    Submitted
    Subjects:Science > Physics
    Department:Faculty of Science > Physics
    Depositing user: Pure Administrator
    Date deposited:21 Sep 2021 12:40
    Last modified:14 Apr 2024 00:55
    URI:https://strathprints.strath.ac.uk/id/eprint/77842
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